Device for supplying an active developing agent into a developing tank

ABSTRACT

An improved device for supplying an active developing agent to the developing tank of an electrophotographic copying apparatus as a function of the passage of a sheet through the copier, wherein the improvement comprises a mechanism, adjustable at different speeds by means of the actuating drive of the apparatus and as a function of a copying process, and actuating an actuator for effecting the addition of an additional active agent to the developer.

United States Patent [72] Inventor Walter Limberger Hamburg-Poppenbuttel. Germany 21 1 Appl. No. 776,063

[22] Filed Nov. 15, I968 [45] Patented July 6, 1971 [73] Assignee Flrnta Lumoprint Zindler KG Hamburg, Germany [32] Priority Nov. [7, i967 [33] Germany [54] DEVICE FOR SUPPLYING AN ACTIVE DEVELOPING AGENT INTO A DEVELOPING TANK 13 Claims, 8 Drawing Figs.

52 U.S.Cl ass/1o, 95/89 151 lnt.Cl. G03g9/04 [50] FieldofSearchmhW 355/10, l3, l4. l02. I09. 110; 95/89 [56] v References Cited UNITED STATES PATENTS 3,192,897 7/1965 Young. .r... 355/l0X 3,299,787 l/l967 Kolb........, 355/l0 Primary Examiner-Samuel 5. Matthews Assistant Examiner-"Monroe H. Hayes Attorney-McGlew and Toren ABSTRACT: An improved device for supplying an active developing agent to the developing tank of an electrophotographic copying apparatus as a function of the passage of a sheet through the copier, wherein the improvement comprises a mechanism, adjustable at difierent speeds by means of the actuating drive of the apparatus and as a function of a copying process, and actuating an actuator for effecting the addition of an additional active agent to the developer.

PATENTED JUL 6:911

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DEVICE FOR SUPPLYING AN ACTIVE DEVELOPING AGENT INTO A DEVELOPING TANK DESCRIPTION The invention relates, as indicated, to a device for supplying an active developing ingredient to a developing tank of a photoelectric copying apparatus as a function of the passage of a sheet through this photocopier.

Particularly in photoelectric copying apparatus, a so-called toner is used as developer which is present in the form of a dispersion in the developing tank, through which pass the sheets carrying the latent electrostatic pictures. This toner is consumed by being deposited on the sheets for developing the pictures and the dispersion must therefore be brought up to the required strength by supplying new toner.

It is already known to provide a toner container with a metering valve with a manual lever, opening of which causes fresh toner to flow into the developing tank.

It is also known to carry out this addition as a function of the number of copies made in the copying apparatus.

However, this addition may be insufficient, because the quantity of toner consumed differs according to the extent of the dark surfaces in the copies.

There are known in the art very complicated photoelectric monitoring devices with light barriers; these devices scan the type of picture on the original and/or on the copy by means of photoelectric cells and evaluate the resulting signal currents for operating the supply of toner. This construction requires extensive controls, because the signals must be amplified to render them suitable for this purpose and because characteristics of the signal currents must be further selectively amplified to produce the necessary differences between signals required to obtain an effective control.

It is therefore an object of the invention to provide a simple, and more particularly, a mechanical device, whereby the further supply of developer or toner may be adapted to the prevailing conditions, and which not only ensures a functional reliability, but also makes this adaptation possible in a relatively simple manner.

It is a further object of the invention to provide a device of the type hereinbefore mentioned, whereby the addition of developing fluid is effected by mechanical means.

It is a further object of the invention to provide a device of the type hereinbefore mentioned, comprising means which are particularly easily manipulated, and whereby the addition of the developing fluid is effected as a function of the number of copies produced in the apparatus.

It is a further object of the invention to provide a device of the kind hereinbefore mentioned, comprising particularly advantageous actuating means for the actuating mechanism for adding the developing fluid, in which the drive of the apparatus for actuating the device for adding the developer is loaded as little as possible to prevent shocks affecting the actuating drive.

The invention is based on a supply as a function of the number of copies, but provides a device actuable by the drive of the apparatus as a function of a copying process and adjustable at different rhythms, wherein the device operates an actuating member for supplying additional developing fluid.

In this manner, the operator, observing the dark areas of the copies produced, can select the necessary rhythm which is then repeated once for every copy, or once for several copies, until the setting is altered.

A device of this kind can be made with mechanical means and avoids thereby the complicated photoelectric and electronic equipment.

A preferred embodiment of the invention comprises a control lever, in the path of which is mounted a cam roller with different stepped cams, and means for relatively adjusting the control lever and the cam roller, with all cams, or in steps only one cam, located in the path of movement of the control lever,

wherein the rotation of the cam roller moves the actuating member, and wherein the cam roller is constructed to be locked by the control lever. The term cam roller used above comprises also other, for example, disc-shaped configurations, and constructions in which the actuating surfaces have the form of raised or recessed portions. The essential feature is that the adjustment is such that each cam or a selected number of cams may be brought into engagement with the control lever for locking the cam roller.

This adjustment is preferably effected by means of a polygonal member with eccentric axis of rotation, providing different distances to the various faces of the polygon, wherein the number of faces corresponds to the number of cams. Preferably, the arrangement comprises a cam roller with four axially extending, projecting, ribs of different lengths and a square adjusting member.

In a preferred embodiment, the cam roller is provided with axial adjusting means. Another embodiment of the invention comprises a control lever which is axially adjustable relative to the cam roller.

In a preferred embodiment of the invention, the polygon is adjustable by means ofa manual lever and a coupling member with an intermittent drive is provided between an apparatus drive and the said actuating member, wherein the steps are transmitted from the coupling to an actuator for adding developer as a function of the engagement between control lever and cam roller.

Using a mechanism, comprising continuously revolving members in the drive of the apparatus and a roller revolving only when a copy passes through the apparatus, the roller is equipped, according to the invention, with a cam arrangement which actuates the control lever with every revolution of the roller for coupling a drive member of the coupling mechanism with the continuously revolving member. The continuously revolving member is preferably a disc and the drive member is a mating disc provided with sector-shaped recesses along its periphery, in which the continuously revolving disc may revolve without making contact, whilst the movement of the takeofl' disc causes contact to be made with the nonrecessed parts of its periphery so as to transmit the drive; the mating disc is provided with a spring whereby, when the mating disc is released by the control lever, engagement is established between the two discs. The number of cams corresponds to the number of sector-shaped recesses, and the cams, cooperating with one arm of the control lever, are so arranged that the mating disc can be locked when one peripheral recess is aligned relative to the drive disc.

The actuating member for controlling the supply of developer is provided with an abutment, cooperating with a stop member on the cam roller and causing an actuation of the actuating member only with a complete revolution of the cam roller. This produces the rhythm control, because the angle of rotation of the cam roller is restricted to one coping process.

The engagement between the cam roller stop and the abutment makes it also possible to lift the actuating member at choice by means of a manual lever, in order to supply more developer so that the operator is in a position to override the control for supplying additional developing agent.

The invention will be further described, by way of example, with reference to the accompanying drawings, showing two embodiments, and in which:

FIG. 1 shows diagrammatically the principle of the control, particularly in the apparatus according to FIGS. 2 to 4;

FIG. 2 is a side elevation of a part of the control mechanism, shown partly in cross section;

FIG. 3 is an end elevation of the arrangement of FIG. 2, with certain parts omitted;

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a partial side elevation, similar to FIG. 2, showing another embodiment;

FIG. 6 is an end elevation of the FIG. 5 arrangement, with certain parts omitted;

FIG. 7 is a partial plan view of FIG. 6;

FIG. 8 is a diagrammatical arrangement of the apparatus, explaining the practical relative association of the different components.

The drawings show only the parts necessary for understanding the invention. Parts which are identical for both embodiments, namely that of FIGS. 2 to 4 on one hand and 5 to 7 on the other, are referenced by the same reference numerals.

Fig. 8 illustrates the arrangement in an apparatus The principle of the invention is explained in FIG. I. The cam roller 1 is shown in developed form. It comprises four cams 2 to 5 of different length, and extending in the axial direction of the roller. A control lever 6, cooperating with these cams, has a hooked end '7 adapted to engage one of the cams 2 to 5 in order to block the driven cam roller 1. The other, lower, arm 8 of the control lever cooperates with a cam arrangement 9 on a roller 10 which revolves only when a copy passes through the copier. This cam arrangement 9 comprises a recess 11. The control lever 6 is biased by a spring 13, anchored on the main frame 12 and keeping the lever in contact with the cam arrangement 9. When the recess 11 reaches its position under the arm of the control lever, the control lever pivots under the action of the spring 13, causing for example, the cam 2 to be released; the cam roller 1 can now revolve under the action of its actuating drive until the next cam, for example the cam 3, causes the cam roller again to be locked by the control lever 6, because the recess 11 is effective only for a short period.

In Fig. l, which illustrates the principle of the embodiment shown in FIGS. 2 to 4, the pivot 14 of the control lever 6 is displaceable in a bearing 15. A stop lever 16 is mounted on this pivot 14 and rests on one surface 17 of a square section member 18. The spring 13 biases the control lever 6 so that this contact is maintained.

The axis of rotation 19 of the square section member 18 is eccentric so that the four surfaces of the square are located at different distances from the axis of rotation. These distances are so dimensioned that, when the square section member is moved, the control lever 6 is positioned in a plane relative to the cam roller so that either all four cams 2 to 5 make engagement with the control lever 6, or only the cams 3 to 5, or the cams 4 and 5, or, if the stop lever rests on the side 20 of the square section member, which is nearest to the axis of rotation, only the cam 5 can cooperate with the control lever 6.

The other Figures show how this principle is applied to actuate a device for topping up developing fluid in a copier.

FIGS. 5 to 7 show an embodiment in which the control lever remains in its plane, whilst the cam roller 1 is displaced by means of the square section member.

To control the paper run, the copying apparatus comprises a continuously revolving roller 21, driven via means, not shown, from the main drive of the apparatus, and a stepping or intermittent drive roller 22, associated with the continuously revolving roller 21, and having an axial flattened portion 23. A copy sheet can be inserted, as already proposed, into the gap formed in this way. When, by feeding an original at another point of the apparatus, a lever is depressed, the intermittent drive roller is mechanically released. Its shaft carries a crank 24, the other end of which is biassed by a spring 27 mounted at on the main frame 26, whereby the intermittent drive roller 22 is rotated after its release in the direction of the arrow until its periphery, adjacent to the said recess or flattened portion 23, makes contact with the continuously driven roller 21. This causes the intermittent drive roller 22 to be rotated through 360 until the flattened portion 23 is again opposite the continuously driven roller 21. Then, the intermittent drive roller can either be stopped by a locking mechanism or may be released for a further revolution. However, this is a problem of the apparatus control, not forming part of the invention, and is mentioned merely to demonstrate the conditions for the control principle according to the invention, with a continuously revolving part and with a roller which makes only a 360 revolution as a function of the passage of a copy through the apparatus.

The roller 21 corresponds to the roller 10 in FIG. I. The shaft of the roller 21 carries the cam arrangement 9 with the cam recess lll. The length of this cam arrangement is such that the arm 8 of the control lever remains always within the range of the cam recess 11, even when its other arm 7 is moved in the axial direction of the cam roller 1.

The end of the arm 8 of the control lever 6 forms a hook 28 which can engage into the recess 11. This recess 11 has a leading step and its trailing end leads tangentially to the periphery of the cam arrangement 9.

In the embodiment shown in the drawing, the two arms 7 and 8 are offset relative to each other (see FIG. 3). The hub 29 is mounted on the shaft 14, mounted axially movably in the bearing 15 in the main frame 26. The bearing has the form ofa bush. Mounted on the other end of the shaft by means of a clip 30 is the stop lever 16, being a crank lever in the embodiment of FIGS. 2 to 4, and resting on the square section member 18. The spring 13 biassing the lever 6 is shown best in FIGS. 2 and The cam roller 1 is adapted to be rotated about a shaft 31, located in the main frame 26. A mating disc 32 with four peripheral sector-shaped recesses 33, 34, 35 36 is rigidly connected with the cam roller 1. A drive disc 37 is mounted on the shaft of the roller 22 in the same plane and in alignment with the mating disc 32. The arrangement is such that, when the continuously revolving drive disc is opposite one of the sector-shaped recesses, for example, the recess 34, no contact exists between the drive disc and the mating disc, whilst driving engagement is established, when the drive disc is opposite the unrecessed periphery of the mating disc.

The mating disc is provided with four pins 38 to 41; a leaf spring 42 with a hooked end 43 is mounted in the path of movement of these pins. The hooked or curved end 43 of the leaf spring 42 is so formed that the spring is tensioned when affected by a pin, revolving in an anticlockwise direction. When the mating disc is at standstill, with one of the recesses in alignment with the drive disc 37-, the spring 42 is tensioned, for example, against the pin 41. When the mating disc is released in the manner described further below, the spring 42 pushes the mating disc into engagement with the drive disc. It may be seen that an arrangement of this kind is provided for each peripheral recess.

When the spring 42 is released, it comes to rest on an abutment 44 of the frame 26 and is held thereby in the path of movement of the pins 38 to 41.

In the embodiment illustrated in the drawing, the cam roller 1 has four cams 2 to 5. In this case, the cams serve simultaneously for locking the mating disc 32. When the control lever is pivoted by entering the cam recess 11, the mating disc and with it also the cam disc are rotatively driven until the arm 7 of the control lever locks again against one of the cams 2 to 5. If the setting is such that the control lever cooperates only with the cam 5 (FIG. 1), a rotation through 360 is effected. If the control lever 6 is set in the manner shown in FIG. 1, each rotation amounts to The end face of the cam roller 1 is provided with an actuating lug 45, located near its periphery.

An actuating member 46 in the shape of a lever is mounted in the main frame. The lower end of this lever acts on an actuating member 47 of a metering valve 48, located in the storage tank 49 for the toner. This metering valve is disposed above an inlet 50 into a developing tank 51, through which copying material is passed, by means not shown in the drawing.

The lever 46 has a slot 52, whereby it is guided on a pin 53 on the frame 26. The upper end 54 of the lever 46 has an upwardly open slot 55, whereby the lever is pushed from the bottom, for example, over the extended shaft 31 of the cam roller. A spring 56, mounted with its other end on the frame, pulls the lever towards the top, whilst the lower end of the slot 55 or 52 abuts on the shaft 31 or the pin 53. It may be seen that the lever 46 is retained by bearing plates against axial displacement on the pin 53 and on the shaft 31.

The lever 46 carries an angle piece with a plate 57 so arranged and disposed that this plate 57 is located with the path of movement of the actuating lug 45, if the same is, for example, at a point determined by the horizontal diameter for the cam roller 1. The width of the plate 57 is so dimensioned that, when the cam roller 1 is driven, the actuating lug 45, moving in an anticlockwise sense, causes the lever 46 to move sufficiently downwardly for actuating the metering valve 48, until it leaves to plate 57, as shown on the right side in FIG. 2. Then the lever 46 is again pulled upwards by the spring 56.

The length of the engagement between the actuating lug 45 and the plate 57 is also so dimensioned with regard to the number of cams on the cam roller that the release takes place before the next locking of the cam roller can occur, i.e., in the four-cam construction, before the cam roller has turned through 90.

The square section member 18 is mounted on a tube 48, located rotatably on the frame 26 as by bearings 59, 60. The tube has at the top an adjusting knob 61, associated with a pointer, not shown. By means of this knob 61, the tube 58 with the square section member can be moved to bring one selected surface of the square section member into engagement with the lever 16, controlling thereby the frequency at which the developing fluid in the tank is brought up to strength.

A rod 62 is guided rotatably in the tube 58 and carries at its upper end a pushbutton 63 which protrudes from the knob 61. The lower end of the rod 62 carries an adjusting lever 64 which projects through a hole in the frame 26 and engages into an opening of the lever 46. Thus, the spring 56 carrying the lever 46 also holds the rod .62 with the pushbutton 63 in the raised position. It also follows therefrom that, by depressing the pushbutton 63, the lever 46 can be selectively pushed down for improving the developer independently of the automatic control, to override the same.

When the control lever 6 is set to cooperate only with the cam 5, the developer is improved with every copy, because the cam roller 1 revolves through 360 and displaces thereby the lever 46 once.

If, on the other hand, the adjustment is such as shown in FIG. 1, in which the control lever'6 makes contact with every cam 2 to 5, the cam roller 1 is locked after every quarter revolution through 90 after having been released by the cam arrangement 9. Thus, the developer is improved only after every fourth copy. it can be seen that the rhythm can be changed.

In the embodiment of FIGS. 6 and 7, the control lever 6 is mounted firmly in the frame 26. Accordingly, the cam arrangement 9 can be made shorter.

The shaft 31 of the cam roller carries a spring-67 arranged between the plate 66 guiding the lever 46 and the cam roller 1, axially movable on the shaft 31; this spring 67 tends to push the cam disc down, as viewed in Fig. 7.

A drive disc 68, corresponding to the drive disc 37 in the arrangement of FIGS. 2 to 5, and cooperating with the mating disc 32, must have, in this construction, a greater axial length and be roller-shaped in order to make continuously contact with the mating disc 32 which moves axially on the shaft 31 together with the cam roller 1.

A friction wheel 70 passes through an opening 69 in the frame and runs, via a contact pressure face 71, on the mating disc 32. This contact pressure face 71 is retained on the pins 38 to 41 which cooperate with the spring 42.

The spindle 72 of the friction wheel is mounted on a pivoting lever 73, pivotable about a pivot 74 so that the friction wheel is movable on the shaft 31 to move the cam roller 1.

In FIG. 8, the arrangement is shown diagrammatically in an apparatus, the housing of which contains the component parts. The Figure shows the elements 21, 22, 46, 48, 49, 51 and 61, already described hereinbefore. The actuating mechanism in the zone of the rollers 21, 22 is indicated generally by the unit 81, from which the actuating lever 46 projects downwardly.

it may be seen that the apparatus comprises a holder 82 with a stack 83 ofcopy paper. A withdrawing roller 84 rests on the topmost sheet and is arranged pivotably on a lever 85 of the actuating mechanism and is driven through this lever, which forms simultaneously a transmission element, in the direction indicated by the arrows.

The drive motor 86 is connected by a transmission 87 with the members 88 and 89, on one hand with the actuating mechanism, and more particularly with the continuously revolving roller 21, and on the other hand with conveyor rollers 90, 91 and 92, mounted in the frame or housing and projecting with a peripheral segment over the upper surface 93, for guiding an original over an exposure plate 94. The motor 86 also drives through transmission members 95 to 98 transportation members 99 to 102 which revolve in the sense indicated by arrows, and which may consist of pairs of rollers or of single rollers cooperating with a guide web.

The copying material carried by the actuating mechanism 81 into the guide 103 is carried past an exposure platform 104. Between this platform 104 and the exposure plate 94 is an exposure device, indicated generally at 105, and comprising exposure light sources, objective lenses and the like. The exposed copy material passes through the developing tank and then through a section 106 in a unit 107, in which the developed picture or reproduction is burned in a thermal radiator or the like, and fixed. Then the sheet of copying material is transported through the section 108 into a delivery trough 109, accessible through an opening 110 in the housing 80.

lclaim:

I. An electrophotographic copying apparatus comprising a frame, a developer tank containing a developing fluid which includes a toner dispersed therein, guide means for guiding an exposed copy sheet into said developer tank, a transport device for feeding the copy sheet through said guide means, a storage tank for toner, valve means interconnecting said storage tank and said developer tank for regulating the introduction of toner in the developing lluid in said developer tank, wherein the improvement comprises a device for operat ing said valve means and introducing toner into said developer tank, said transport device including a member arranged to rotate through an angular path as a given length of copy sheet is fed by said transport device, a pivotally mounted control lever in operative engagement with said transport device member and arranged to be pivotally displaced as said transport device member rotates through its angular path, a rotatably mounted actuating device in operative engagement with said transport device and arranged for selectively displacing said device for operating said valve means, said actuating device having adjustable stop means for selectively arresting its rotational movement for regulating its selective displace ment of said device for operating said valve means and thereby controlling the introduction of toner into said developer tank.

2. An electrophotographic copying apparatus, as set forth in claim 1, wherein said actuating device comprises a rotatably mounted cam roller having a plurality of angularly spaced cams thereon positioned in the path of said control lever, an axially extending pivot member, and said control lever being pivotally mounted on said pivot member and being displaceable in the axial direction of said pivot member so that said control lever contacts all or selective ones of said cams as said cam roller rotates.

3. An electrophotographic copying apparatus, as set forth in claim 2, wherein a stop lever being mounted on and extending laterally from said pivot member and being axially spaced from said control lever, a stop member being rotatably supported on an axis of rotation spaced laterally from said stop lever, said stop member having a plurality of stop surfaces thereon each spaced a different distance from the axis of rotation of said stop member, and s spring member for biassing said stop lever against one of said surfaces and axially displacing said control lever for regulating the contacting engagement between said control lever and said cams on said cam roller.

4, An electrophotographic copying apparatus, as set forth in claim 3, wherein said stop member being polygonally shaped and having an eccentric axis of rotation arranged so that each exterior surface of said polygonally shaped stop member is spaced a different distance from the eccentric axis of rotation.

5. An electrophotographic copying apparatus, as set forth in claim I, wherein said transport device comprises a driven roller, a driven disc mounted on said driven roller for rotation therewith, an intermittent drive roller arranged to be driven by said driven roller, a cam member mounted on said intermediate driven member for rotation therewith, said cam member having a recess in its peripheral surface, and said control lever in contact with the periphery of said cam member and being arranged to be pivotally displaced when it enters said recess in said cam member as said cam member rotates.

6. An electrophotographic copying apparatus, as set forth in claim 5, wherein a mating disc being mounted on said cam roller for rotation therewith, said cam roller and said driven roller having their axes disposed in substantially parallel relationship and the periphery of said mating device being arranged so that an angular portion of its periphery is in contact with said drive disc as said cam roller rotates.

7. An electrophotographic copying apparatus, as set forth in claim 6, wherein the peripheral edge of said mating disc having a plurality of angularly spaced sector-shaped recesses therein having a configuration that when said recesses are in juxtaposed relationship to said drive disc, said mating disc and drive disc are in spaced relationship and said driven roller and drive disc can continue to rotate without contacting said mating disc.

8. An electrophotographic copying apparatus, as set forth in claim 7, wherein said mating disc having a plurality of pins extending outwardly from the lateral surface of said mating disc and said pins corresponding in number to and spaced apart in the same angular spacing as said recesses in the periphery of said mating disc, a leaf spring secured to said frame and extending into the path of movement of said pins on said mating disc, whereby when one of the recesses in said mating disc is disposed opposite and in spaced relationship from the peripheral edge surface of said drive disc, one of said pins contacts and tensions said leaf spring so that when said control lever is pivotally displaced by said transport device member, said leaf spring imparts a driving force to said mating disc and cam roller.

9. An electrophotographic copying apparatus, as set forth in claim 8, wherein said device for operating said valve means comprising an elongated lever member having a plate secured thereto and extending laterally therefrom, an actuating lug secured to and extending outwardly from said cam roller and arranged to contact said plate on said lever member as said cam roller rotates for displacing said lever member and operating said valve means for introducing toner into said developer tank.

10. An electrophotographic copying apparatus, as set forth in claim 9, wherein said elongated lever member has a first slot extending in its elongated direction, a pin secured to said frame and extending through said slot for guiding the movement of said lever member, a second slot formed in the end of said elongated lever member opposite its end arranged for operating said valve means, an extension of said cam roller positioned within said second slot for guiding the end thereof, and a spring secured to said elongated lever and to said extension of said cam roller for biasing said elongated lever member away from said valve means. A

l An electrophotographic copying apparatus, as set forth in claim 2, wherein said cam roller comprises a shaft extending axially from said cam roller, an annular plate mounted on and extending outwardly from said shaft, a spring disposed about said shaft and bearing at one end against said plate and at its other end against one end of said cam roller for biasing said cam roller away from said plate, a pivot secured to said frame, a pivoting lever mounted on said pivot and extending generally perpendicularly to the axis of said shaft, a friction wheel secured to the end of said pivoting lever opposite its end mounted on said pivot, said friction wheel being arranged to contact the opposite end of said cam roller from the end thereof against which said spring abuts, whereby in pivoting said pivoting lever about said pivot said friction wheel axially displaces said cam roller against the action of said spring.

12. An electrophotographic copying apparatus, as set forth in claim 3, wherein said control lever comprises a bearing, an elongated pivot axially displaceable in said bearing, a doublearm rocking lever secured to said pivot at a position spaced from said bearing, said double-arm lever comprising a first arm arranged to extend into contact with said transport device and a second arm extending from the opposite side of said pivot from said first arm and being angularly disposed relative to said first arm, a stop lever mounted on said pivot on the opposite side of said bearing from said double-arm lever, said stop lever being arranged to contact one of the stop surfaces of said stop member, a spring secured at one end to said frame and at its other end to said control lever for biasing said stop lever against the stop surface of said stop member.

13. An electrophotographic copying apparatus, as set forth in claim 4, wherein a tube forming the eccentric axis of rotation of said stop member, an adjusting knob secured to said tube at a position spaced from said stop member for rotating said tube and adjusting the stop surfaces of said stop member relative to said control lever, a rod being rotatably supported within and extending through said tube, an adjusting lever secured to one end of said rod and extending into operative engagement with said actuating device, and a pushbutton secured to said rod at the opposite end thereof from said adjusting lever and said pushbutton extending outwardly from said tube so that by depressing said push button said rod and said adjusting lever displace said actuating device for manually operating said valve means. 

1. An electrophotographic copying apparatus comprising a frame, a developer tank containing a developing fluid which includes a toner dispersed therein, guide means for guiding an exposed copy sheet into said developer tank, a transport device for feeding the copy sheet through said guide means, a storage tank for toner, valve means interconnecting said storage tank and said developer tank for regulating the introduction of toner in the developing fluid in said developer tank, wherein the improvement comprises a device for oPerating said valve means and introducing toner into said developer tank, said transport device including a member arranged to rotate through an angular path as a given length of copy sheet is fed by said transport device, a pivotally mounted control lever in operative engagement with said transport device member and arranged to be pivotally displaced as said transport device member rotates through its angular path, a rotatably mounted actuating device in operative engagement with said transport device and arranged for selectively displacing said device for operating said valve means, said actuating device having adjustable stop means for selectively arresting its rotational movement for regulating its selective displacement of said device for operating said valve means and thereby controlling the introduction of toner into said developer tank.
 2. An electrophotographic copying apparatus, as set forth in claim 1, wherein said actuating device comprises a rotatably mounted cam roller having a plurality of angularly spaced cams thereon positioned in the path of said control lever, an axially extending pivot member, and said control lever being pivotally mounted on said pivot member and being displaceable in the axial direction of said pivot member so that said control lever contacts all or selective ones of said cams as said cam roller rotates.
 3. An electrophotographic copying apparatus, as set forth in claim 2, wherein a stop lever being mounted on and extending laterally from said pivot member and being axially spaced from said control lever, a stop member being rotatably supported on an axis of rotation spaced laterally from said stop lever, said stop member having a plurality of stop surfaces thereon each spaced a different distance from the axis of rotation of said stop member, and s spring member for biassing said stop lever against one of said surfaces and axially displacing said control lever for regulating the contacting engagement between said control lever and said cams on said cam roller.
 4. An electrophotographic copying apparatus, as set forth in claim 3, wherein said stop member being polygonally shaped and having an eccentric axis of rotation arranged so that each exterior surface of said polygonally shaped stop member is spaced a different distance from the eccentric axis of rotation.
 5. An electrophotographic copying apparatus, as set forth in claim 1, wherein said transport device comprises a driven roller, a driven disc mounted on said driven roller for rotation therewith, an intermittent drive roller arranged to be driven by said driven roller, a cam member mounted on said intermediate driven member for rotation therewith, said cam member having a recess in its peripheral surface, and said control lever in contact with the periphery of said cam member and being arranged to be pivotally displaced when it enters said recess in said cam member as said cam member rotates.
 6. An electrophotographic copying apparatus, as set forth in claim 5, wherein a mating disc being mounted on said cam roller for rotation therewith, said cam roller and said driven roller having their axes disposed in substantially parallel relationship and the periphery of said mating device being arranged so that an angular portion of its periphery is in contact with said drive disc as said cam roller rotates.
 7. An electrophotographic copying apparatus, as set forth in claim 6, wherein the peripheral edge of said mating disc having a plurality of angularly spaced sector-shaped recesses therein having a configuration that when said recesses are in juxtaposed relationship to said drive disc, said mating disc and drive disc are in spaced relationship and said driven roller and drive disc can continue to rotate without contacting said mating disc.
 8. An electrophotographic copying apparatus, as set forth in claim 7, wherein said mating disc having a plurality of pins extending outwardly from the lateral surface of said mating disc and said pins corresponding in number to And spaced apart in the same angular spacing as said recesses in the periphery of said mating disc, a leaf spring secured to said frame and extending into the path of movement of said pins on said mating disc, whereby when one of the recesses in said mating disc is disposed opposite and in spaced relationship from the peripheral edge surface of said drive disc, one of said pins contacts and tensions said leaf spring so that when said control lever is pivotally displaced by said transport device member, said leaf spring imparts a driving force to said mating disc and cam roller.
 9. An electrophotographic copying apparatus, as set forth in claim 8, wherein said device for operating said valve means comprising an elongated lever member having a plate secured thereto and extending laterally therefrom, an actuating lug secured to and extending outwardly from said cam roller and arranged to contact said plate on said lever member as said cam roller rotates for displacing said lever member and operating said valve means for introducing toner into said developer tank.
 10. An electrophotographic copying apparatus, as set forth in claim 9, wherein said elongated lever member has a first slot extending in its elongated direction, a pin secured to said frame and extending through said slot for guiding the movement of said lever member, a second slot formed in the end of said elongated lever member opposite its end arranged for operating said valve means, an extension of said cam roller positioned within said second slot for guiding the end thereof, and a spring secured to said elongated lever and to said extension of said cam roller for biasing said elongated lever member away from said valve means.
 11. An electrophotographic copying apparatus, as set forth in claim 2, wherein said cam roller comprises a shaft extending axially from said cam roller, an annular plate mounted on and extending outwardly from said shaft, a spring disposed about said shaft and bearing at one end against said plate and at its other end against one end of said cam roller for biasing said cam roller away from said plate, a pivot secured to said frame, a pivoting lever mounted on said pivot and extending generally perpendicularly to the axis of said shaft, a friction wheel secured to the end of said pivoting lever opposite its end mounted on said pivot, said friction wheel being arranged to contact the opposite end of said cam roller from the end thereof against which said spring abuts, whereby in pivoting said pivoting lever about said pivot said friction wheel axially displaces said cam roller against the action of said spring.
 12. An electrophotographic copying apparatus, as set forth in claim 3, wherein said control lever comprises a bearing, an elongated pivot axially displaceable in said bearing, a double-arm rocking lever secured to said pivot at a position spaced from said bearing, said double-arm lever comprising a first arm arranged to extend into contact with said transport device and a second arm extending from the opposite side of said pivot from said first arm and being angularly disposed relative to said first arm, a stop lever mounted on said pivot on the opposite side of said bearing from said double-arm lever, said stop lever being arranged to contact one of the stop surfaces of said stop member, a spring secured at one end to said frame and at its other end to said control lever for biasing said stop lever against the stop surface of said stop member.
 13. An electrophotographic copying apparatus, as set forth in claim 4, wherein a tube forming the eccentric axis of rotation of said stop member, an adjusting knob secured to said tube at a position spaced from said stop member for rotating said tube and adjusting the stop surfaces of said stop member relative to said control lever, a rod being rotatably supported within and extending through said tube, an adjusting lever secured to one end of said rod and extending into operative engagement with said actuating device, and a pushbutton secured to said rod at the opposite end thereof from said adjusting lever and said pushbutton extending outwardly from said tube so that by depressing said push button said rod and said adjusting lever displace said actuating device for manually operating said valve means. 